Caspase-Glo 3/7 assay.

To assess if NVS-ZP7–1 was stimulating the activity of caspase 3/7, an indicator of apoptosis, the Caspase-Glo 3/7 assay system (Promega) was used. Included in this assay were control compounds including staurosporine (Calbiochem), which is known to induce apoptosis, along with negative controls that included DMSO and NVS-ZP7–2 (inactive version of NVS-ZP7–1). The T-ALL cell lines TALL-1 and SUPT11 were used for this assay. Cells (1 × 10³) were plated into 384-well assay plates and treated with a 10 μM final concentration of compound. Caspase-Glo 3/7 reagent was prepared according to the Promega protocol and added to the cells 48 h after compound addition. Each sample was incubated with the Caspase-Glo 3/7 reagent for 45 min and then luminescence (relative luminescence units) was read out on the EnVision multilabel plate reader (PerkinElmer). Bar charts were then generated using the luminescence reads in GraphPad Prism.